In case you might have missed it, Saudi Arabia and Iran are teetering on the edge of open war.

For years, the two regional powers have been engaged in at least three proxy wars across the Mid-East.

In Syria, the Quds and the IRGC have been fighting to bolster Bashar al-Assad’s depleted forces since at least 2012, while the Saudis and the other Gulf monarchies have lent assistance to the various Sunni rebel groups fighting to destabilize the government in Damascus.

In Yemen, Iran-backed Houthi militiamen drove President Abd Rabbuh Mansur Hadi from the country last year, prompting Riyadh to intervene in order to prevent Tehran from establishing what would amount to an Iranian colony on the kingdom’s southern border.

And in Iraq, the sectarian strife is as divisive as ever, with Iran dominating politics in Baghdad and the Ayatollah’s Shiite militias stoking fear in the hearts of the country’s Sunni minority even as the fighters function as the most effective force battling ISIS.

Through it all, Riyadh and Tehran haven’t yet squared off directly. That is, where Saudi Arabia has troops and planes Iran fights by proxy and where Iran has ground troops, the Saudis are fighting through their own proxies.

Saudi Arabia’s move to execute prominent Shiite cleric Nimr al-Nimr has the potential to change all of that.

The Sheikh was a leading voice among Saudi Arabia’s dissident Shiite minority and his death sparked outrage and street protests across the Shiite community. Riyadh cut diplomatic ties with Tehran after the Saudi embassy was torched in Iran and the Sunni monarchies quickly followed suit.

Now, the stage is set for a potentially disastrous sectarian conflict that could reverberate for decades to come. Underscoring just how contentious the situation has become, Iran foreign minister Javad Zarif and Saudi Prince Turki al-Faisal were reportedly involved in a “clash” at a closed-door meeting at the World Economic Forum in Davos on Wednesday.

“The barbed exchange between Saudi Prince Turki al-Faisal and Iranian Foreign Minister Javad Zarif at an invitation-only meeting on Wednesday underlined the hostility between the two Gulf rivals, who are waging proxy wars in Syria, Yemen and Iraq,” Reuters reports before recounting the spat. "It was a dialogue of the deaf," on witness recalls. Here’s more:

U.N. special envoy on Syria Staffan de Mistura, former U.N. Secretary-General Kofi Annan, former Arab League Secretary-General Amr Moussa of Egypt, the foreign ministers of Italy and Austria and officials from Turkey and several other Western nations were also around the table.

De Mistura opened the meeting by saying the time was ripe for the Geneva peace talks because outside powers all wanted a political solution to the five-year-old civil war in Syria, the participants said.

However, several speakers questioned Russia's motives for intervening in the conflict since September with air strikes in support of President Bashar al-Assad. They cast doubt on whether Moscow and Tehran wanted any deal that would involve Assad's eventual departure.

Zarif said Iran supported a political solution and had set out a four-point peace plan when it was finally invited to join international diplomacy on Syria last year. It had been excluded for years at U.S. and Saudi insistence.

Without naming any country, he took a veiled swipe at Riyadh by condemning those, he said, who fanned and exploited sectarian differences between Sunni and Shi'ite Muslims across the region.

At his news conference, Zarif accused Saudi Arabia of having spent millions of dollars to lobby the U.S. Congress against an international deal on Iran's nuclear program. An agreement with Iran led to the lifting of U.N. sanctions on the country this week.

He said Riyadh had panicked after the embassy attack and the Saudis needed to "come to their senses".

Prince Turki hit back in the closed session, blasting Iran's role in the Syria conflict, the participants said. Quoting an Arabic saying, he told Zarif:

"I really like what you say but when I look at what you do, I wonder."

Prince Turki, the 70-year-old youngest son of the late King Faisal, accused Iran of having 10,000 fighters on the ground in Syria supporting Assad, participants said. He described the Syrian leader as a "terrorist killing his own people" who was directly kept in power by Tehran, the participants said.

One participant said the prince's remarks were sharper than expected and shocked some of those attending the meeting.

There were already doubts as to whether John Kerry and Sergei Lavrov would succeed in bringing the "moderate" Syrian opposition to the bargaining table in Geneva next week and the verbal jousting match between Zarif and Prince Turki suggests that diplomacy may be impossible given the current hostilities between Riyadh and Tehran.

Meanwhile, Pentagon chief Ash Carter just can't seem to understand why the Sunni powers aren't more helpful in fighting ISIS. “It’s strange that a Sunni extremist group running rampant in Iraq and Syria should attract as little Sunni Arab counterweight as it has so far,” Carter told Bloomberg TV on Friday.

No, Mr. Carter, it is not "strange", nor is it a coincidence.

There is no "Sunni Arab counterweight" because Saudi Arabia promotes a similar brand of ultra puritanical Islam as that espoused by ISIS. Once again, if the US wants help in defeating Islamic State, Ash Carter may want to look to the nations that actually have a vested interest in bringing about the group's demise, namely Iran and Russia. As long as Washington insists on keeping up this charade wherein everyone pretends to be mystified as to why the Gulf monarchies and Turkey don't seem all that interested in seeing ISIS destroyed, this ridiculous dog and pony show will continue, and Javad Zarif's contention that it is in fact the Saudis that are fomenting sectarian discord will continue to fall on deaf ears.